(EA71) When I give it a little gas, it revs up sputter-ly, when I give it half or full throttle, it dips down for a split second, then jumps up rough and slowly. Similar to when you get some water in your carb. It makes starting off in 1st really hard, especially on a hill. The problem isn't as bad when fully warmed up, but still there. At high RPM (like 2800+ I guess, no tach) it performs beautifully. I put in new NGK V-powers and they helped but only a little. Air filter is brand new.

 

Might the heads being really dirty have something to do with it? The PVC vents are caked with oil crud, but cleaning them out would have knocked it into the heads.

sounds like an accellerator pump issue to me. Pretty easy to get to. Remove the air cleaner, then remove the top portion of the carb (should be like 6 small screws) and once removed, it'll be a "pump" that pumps fuel into the barrel of the carb. When they are on their way out, it'll sputter when giving it gas. You'll have to get a carbr ebuild kit IIRC which is like $25 from Schucks last time I bought one.

Yep, accelerator pump, or clogged accelerator pump jet.

 

Todd

let us know if that helps, sounds like the same problem mine has that didn't go awya after a pump replacement, I dialed it out a little after I put a new rotor on it

Often the little jet that the accelerator pump pushes fuel through clogs. Use a small piece of wire to clean the opening out.

 

Todd

also check the check ball at the bottom of the well.

 

it is the one way valve that prevents the pressure from returning to the bowl.

I sprayed a ton of carb cleaner while revving the poo out of it yesterday and that improved the idle a lot but didn't clear up the sputter like I hoped. I will try to pull off the carb thing tomorrow, thanks guys